Evaluation of the type V pit pattern in the lesions of colonic Tis and T1 cancer

Background:  The usefulness of magnifying videoendoscopic pit pattern diagnosis has been recognized in the differential diagnosis of colonic neoplasms. Also, the correspondence between lesions with a type V pit pattern and cancer has been emphasized. We evaluated the relationship between the type V pit pattern and carcinoma in situ or subdivided submucosal invading carcinomas.Methods:   During the period from May 1997 to December 2001, a total of 8696 colonoscopies were performed and 6672 colorectal lesions were detected. Colorectal lesions (47.7%; 3181/6672) were examined by videoendoscopic magnification. The type V pit pattern was divided into two groups: VI and VN. The submucosal extensions of cancers were classified as sm1, sm2 and sm3 according to the vertical level of invasion. All Tis (n = 57) and operated T1 carcinomas (n = 69) with the type V pit pattern were selected for this study.Results:  Cancer invasion with the type VI pit pattern was limited up to sm2, and the type VN pit pattern was closely related to sm3 extension in protruded type (P = 0.0005). The frequency of the appearance of the type VI pit pattern decreased and that of the type VN pit pattern increased as the invasion extended deeper into the submucosal layer in superficial‐type cancers (P < 0.0001).Conclusions:   Superficial type cancers well reflected the submucosal infiltrating cancer glands when their surface structure had a type VN pit pattern. In contrast, only 20% of sm2 cancers presented a type VN pit pattern among the protruded types.